Numerical Statistical Measures

Question 1

what is standard deviation

Answer 1

gives an idea of how far away from the mean the data values tend to be
Measure of spread

Question 2

formula for mean

Answer 2

sum ÷ total

Question 3

standard deviation formulae

Answer 3

in formula booklet

Question 4

what is variance

Answer 4

standard deviation = √(variance)
(variance)² = standard deviation

Question 5

how to calculate mean from grouped data

Answer 5

use x = group midpoint

BE CAREFUL
continuous data- may be rounded to [nearest minute]: make sure to unround to get complete/continuous data

Question 6

flaws of linear interpolation

Answer 6

Assume the frequency within a group is uniformly distributed

Question 7

Measures of central tendency

Answer 7

Mean
Median
Mode

Question 8

Measures of spread

Answer 8

Standard deviation
Interquartile range
Range

Question 9

Measures of weight

Answer 9

Mean
Standard deviation

Question 10

Measures of position

Answer 10

Median
Interquartile range

Question 11

Coding/scaling data : mean

Answer 11

Adding- increases by the same amount
Multiplying- changes by same proportion

Question 12

data coding/scaling: standard deviation

Answer 12

adding- no change (constant difference between parts)
multiplying- changes by same proportion